// return code
export enum RC {
    SUCCESS,
    USERNAME_EXIST,
    USERID_NOTEXIST,
    INVALID_ARGUMENT,
    INTERNAL_ERROR,
    PASSWORD_INCORRECT,
    RECEIVERID_NOTEXIST,
    GROUPNAME_EXIST,
    GROUPID_NOTEXIST,
    FRIENDCREATE_FAILURE,
    ID_NOTEXIST,
}